The Kabal of the Seventh Seal is young in comparison to most others.
The Archon of the Kabal, Lord Angaurrith, is the bastard son of Asdrubael Vect and Aurelia Malys. During the time where Vect had Malys as a consort, she bore a child. Vect did not know about the boy until much later. After Angaurrith was born, Vect dismissed Mayls from his court, and she fled to the Webway, leaving her son to fend for himself before he was even a century old. He turned around and joined the Kabal of the Black Heart, wanting revenge on Vect for what he did to his mother.
If it is possible for the Dark Eldar to love someone, Angaurrith loved his mother dearly. He hated any creature who had not felt the pain he felt as he watched his mother flee from her humiliation. Only a shoty five years into his experience with the Black Heart, Angaurrith has been moved into a Dracon position, and in another three years he was one of Vect's personal favorites. Angaurrith led a squad of four trueborn known as the "Executioners", who all used darklight weapons for quick kills. The Executioners were loyal to Angaurrith, even more so than they were to Vect. Angaurrith was called to see Vect after a particularly daring realspace raid.
Vect was very pleased with the work of his Dracon, and had an assasination mission for him and the Executioners to do. Vect wanted them to kill Lady Malys, who had just resurfaced as Archon of the Poisoned Tongue. Angaurrith did not know that Vect knew about his relation to Malys, though he did not know that he was Angaurrith's father. Angaurrith left Vect and went to the Executioners, explaining the situation. They left for the Poisoned Tongue on board Angaurrith's personal Raider, the Chariot of Bones. They arrived to find Malys awaiting them with her guard, but when she saw her it was her son who was sent, she allowed herself a slight smile. Angaurrith told his mother that he intended to enter the Webway and escape Vect, so to avoid his wrath. That very night, they left Commorragh behind.
A few hundred years later, the name of a new Kabal began to creep into Commorragh. That Kabal was the Seventh Seal.
Angaurrith rarely left his dark home, residing in a small corner of the Webway that he had found. He ran his Kabal through his four loyal trueborn, now his lesser Archons. Angaurrith has been transformed though, for while wandering the Webway the five Dark Eldar came upon a Bloodthirster, one of the Greater Daemons of Khorne. Angaurrith struck a deal with the Daemon, challenging it to one on one combat. If the Daemon won, he would be allowed to possess him amd gain all his power, but if Angaurrith won the Daemon was to grant him his power and realm to call their own. The Daemon won the combat, bu unfortunately for the Daemon, Angaurrith had a stronger will and a stronger motivation. For the Daemon, all this deal was for was more power, but for Angaurrith it was for something more...he wanted revenge. Angaurrith's blackened soul overwealmed the Daemon, granting Angaurrith with the power and knowledge he craved, and absorbing the Daemon. His skin is now as black as night, not unsimilar to the Mandrakes, from his back he sports batlike wings, and his eyes shine a blood red colour. His kabalites have the same black skin and red eyes, as to join the Seventh Seal you must venture into the Webway, and uopn finding them drink a vial of the Blood of the Archon. If you survive, you are admitted into the Kabal, pledging your loyalty to the half-Daemon megalomaniac.
The Seventh Seal avoids the other Kabals as much as it can, keeping out of Commorragh unless they are needed there. Their only true "allies" are the Poisoned Tongue, though the interaction between the two is kept at a minimum. The Imperium has only seen this Kabal in action over the last hundred years, noting that they do not generally strike anything but roaving Space Marines. They are known to prey upon the Tau quite often, and of late they have been striking at Necron forces. The Seventh Seal has a Cult and a Coven that share a space with it in their pocket realm, and though the wyches skills rival those of the Cult of Strife, they rarely venture to the Arena.
Thus said, Angaurrith is waiting for the moment where Vect shows weakness. Daemonic energies and Eldar technology have kept them hidden from Vect, while a troupe of Harlequins known as the Messengers of Murekhalir feed Angaurrith information from Commorragh.
Since his ascension to half-Daemonhood, Malys has only seen her son one time. She ventured with the Troupe leader of the Messengers to his dark realm. Upon seeing her cursed son, she actually showed a hint of sadness, allowing a single tear to slip from her eyes. Angaurrith saw this, and slipped back into the shadows.
All that is left of this tale is what lies in the future. Whether Angaurrith succumbs to his Daemonic taint, or is able to attain his goal of revenge on Vect has yet to be seen, but soon all of Commorragh will know and fear the name of the Kabal of the Seventh Seal.